The inventive concepts relate to semiconductor devices and methods for manufacturing the same. More particularly, the inventive concepts relate to semiconductor devices including capacitors and methods for manufacturing the same.
Capacitors having sufficient capacitances in a limited area have been needed as semiconductor devices have become increasingly highly integrated. The capacitance of a capacitor is directly proportional to a surface area of an electrode and a dielectric constant of a dielectric layer that comprises a capacitor, but is inversely proportional to an equivalent oxide thickness of the dielectric layer. Therefore, to increase the capacitance of a capacitor in a limited area, the surface area of the electrode may be increased by using a three-dimensional structure for the capacitor, by reducing the equivalent oxide thickness of the dielectric layer, and/or by using a material having a high dielectric constant as the dielectric layer.
To increase the surface area of the electrode, a height of a bottom electrode (or a storage electrode) may be increased, and/or an effective surface area of the bottom electrode may be increased using a hemi-spherical grain (HSG), and/or the bottom electrode may have a one cylindrical storage (OCS) shape to use both an inner surface area and an outer surface area of the OCS shape. In addition, materials having a high dielectric constant may be selected, for example a metal oxide layer (e.g., TiO2 or Ta2O5) and/or a ferroelectric having a perovskite (e.g., PbZrTiO3 (PZT), or BaSrTiO3 (BST)).